Novel Methods in Multiple Criteria Decision-Making Process (MCRAT and RAPS)—Application in the Mining Industry

Multiple criteria decision making (MCDM) is a supporting tool which is widely spread in different areas of science and industry. Many researchers have confirmed that MCDM methods can be useful for selecting the best solution in many different problems. In this paper, two novel methods are presented and applied on existing decision-making processes in the mining industry. The first method is multiple criteria ranking by alternative trace (MCRAT) and the second is ranking alternatives by perimeter similarity (RAPS). These two novel methods are demonstrated in decision-making problems and compared with the ranking of the same alternatives by other MCDM methods. The mining process often includes drilling and blasting operations as the most common activities for exploitation of raw materials. For optimal blasting design it is important to select the most suitable parameters for the blasting pattern and respect characteristics of the working environment and production conditions. By applying novel methods, how to successfully select the most proper blasting pattern respecting all conditions that must be satisfied for economic aspects and the safety of employees and the environment is presented.

Explicit dynamics based numerical simulation approach for assessment of impact of relief hole on blast induced deformation pattern in an underground face blast

The breakage of rock mass by blasting has many challenges. The optimal breakage in an underground development face/tunnel blast is dominantly dependent on the relief area provided to the blast holes. The cut portion in the burn cut face blast is significantly important to achieve the controlled deformation due to the blast. This paper has discussed the impact of the number and diameter of the relief holes on the breakage pattern of the rock. The numerical simulation with varying numbers and diameter of relief hole was carried out for this purpose. Finite element modeller explicit dynamics of Ansys-Autodyn was used for the simulation work. The isosurface of non-deformed zone was plotted to compare the extent of deformation under varying conditions of relief holes. The analysis shows that the higher number of relief holes with optimum diameter gives more controlled deformation than single relief hole with larger diameter. The nearfield vibration was also recorded by placement of seismograph. The waveform analysis of the recorded vibration was carried out. The redesigning of the blasting pattern was done using the results of numerical simulation and waveform analysis. The redesigned pattern consists of four relief holes of 115 mm diameter. The blasting output with the revised design has resulted into the considerable improvements in the pull and reduction of overbreak. The revised pattern has addressed the issue of the socket formation at the site.

PENGGUNAAN EXPLOSIVE LOW DENSITY PADA PELEDAKAN AREA DI BAWAH RADIUS AMAN MANUSIA DAN PENINGKATAN PRODUKTIVITY ALAT GALI DI AREA TERSEBUT PADA PENAMBANGAN BLOK B1 PIT C2 SAMBARATA MINE OPERATION PT BERAU COAL

ABSTRAK Pit C2, merupakan salah satu blok penambangan Site Sambarata Mine Operation yaitu masuk ke dalam blok B1. Merupakan pit aktif hingga sekarang dimana penambangan dari 2018 hingga akhir 2019 telah mengarah ke pemukiman hingga boundary pit (2019) berjarak 200 m ke pemukiman terdekat dan area tersebut penambangan menggunakan peledakan.Volume overburden pada area tersebut yang termasuk zona dibawah 500 m jarak aman peledakan adalah 1.340.281 bcm dan coal sebesar 175.237 ton dengan SR 7,65. Telah diterapkan beberapa taknik peledakan pada area tersebut ,yaitu salah satunya dengan sistem peledakan elektronik detonator dengan berbagai improvmentnya diantaranya : pola segementasi, segmentasi bufferzone, electronic detonator with air decking dan penggunaan matrial stemming full gravel. Kendala yang timbul adalah masalah efek peledakan yaitu vibrasi dan fly rock dengan jarak tersebut serta pembentukan bench height yang tidak maksimal karena adanya limit kedalaman lubang maksimal 5 m di area 500-300 m dari pemukiman, sehingga produktivity unit (PC 2000) tidak maksimal dan menimbulkan blasting cost yang tinggi. Penggunaan Explosives Low Density (0,7-0,8 gr/cc), di area < 500 m dari pemukiman bisa menambah kedalaman lubang bor hingga kedalaman 7 m, sehingga menambah volume peledakan tanpa mengubah parameter peledakan sebelumnya yaitu : pattern peledakan, charging weight dan penggunaan sistem elektronik detonator dan juga bisa menggunakan sistem peledakan nonel. Dengan explosive low density pengingkatan column raise lubang ledak menjadi 1,3 m. Dari data digging time unit loader (PC 2000), mampu mencapai 9,9 detik dari target maksimal 11 detik, produktivity di atas 700 bcm/jam dan vibration effect yang dihasilkan masih di bawah 2,2 mm/sec (PVS) yang menjadi patokan site. Sehingga penggunaan explosive low explosive ini bisa mempercepat sekuen penambangan di pit C2 sesuai dengan boundary disain 2019 Kata kunci : Low density,Ground vibration, fly rock , productivity ABSTRACT Pit C2, is one of the Mining Samntbarata Mine Operation mining blocks, which is included in Block B1. It is an active pit up to now where mining from 2018 to the end of 2019 has led to settlements to the boundary pit (2019) within 200 m to the nearest settlement and the area is mining using blasting. Overburden volume in the area which includes zones below 500 m safe blasting distance is 1,340,281 bcm and coal of 175,237 tons with SR of 7.65. Several blasting techniques have been applied in this area, one of which is an electronic detonator blasting system with various improvements including: Segmentation pattern, buffer zone segmentation, electronic detonator with air decking and the use of full gravel matrial stemming. The obstacle that arises is the problem of blasting effects namely vibration and fly rock with that distance and the formation of bench height that is not optimal because of the maximum hole depth of 5 m in the area of 500-300 m from the settlement, so the productivity unit (PC 2000) is not optimal and causes high blasting cost. The use of Explosives Low Density (0.7-0.8 gr / cc), in the <500 m area of the settlement can increase the depth of the drill hole to a depth of 7 m, thus increasing the volume of blasting without changing the previous blasting parameters namely: blasting pattern, charging weight and the use of an electronic detonator system and can also use a nonel blasting system. With explosive low density the column raising the explosive hole to 1.3 m. From the digging time unit loader data (PC 2000), it can reach 9.9 seconds from the maximum target of 11 seconds, productivity above 700 bcm / hour and the resulting vibration effect is still below 2.2 mm / sec (PVS) which is the benchmark site . So that the use of low explosive explosives can accelerate the mining sequence in pit C2 in accordance with the 2019 design boundary. Kata kunci : Low density,Ground vibration, fly rock , productivity

PGV-prediction for production blasts at the iron ore mine Mt. Erzberg, Austria

&lt;div&gt; &lt;p&gt;A seismic site characterization of the iron ore mine at Mt. Erzberg was performed in November 2016. The covered area measured about 4 km&amp;#178; within the active mine and the surrounding village. Within 4 weeks 125 3-component-geophones recorded 31 seismic events including production blasts. This data allowed for the computation of P and S velocity models. Which in turn were the basis for seismic wave field modelling with an elastic FD code. These simulations were used to calculate optimized blasting patterns for minimal vibrations at sensitive targets, like settlements and infrastructure, which were tested in a second and third experiment in June and October 19. (see contribution by Trabi et al.)&amp;#160;&lt;/p&gt; &lt;/div&gt;&lt;div&gt; &lt;p&gt;In this study a statistical analysis of the resulting PPV-vector at any given geophone position was done, utilizing recorded blasts from 3 experiments. Using a scaled distance method, one can establish relationships between blast intensity, distance and ground vibrations.&amp;#160;When compared to the PPV prognosis from the simulations, this analysis allows for assessments on prediction accuracy. General trends in PGV estimation can also be used to create site amplification factors to further enhance optimized blasting pattern calculations.&amp;#160;&lt;/p&gt; &lt;/div&gt;&lt;div&gt; &lt;p&gt;This study is part of a large interdisciplinary EU funded project called SLIM, which focuses on sustainability in mining.&amp;#160;&lt;/p&gt; &lt;/div&gt;

Procedure of computation and automatic marking of drill hole spacing at excavation of horizontal workings

Contemporary approaches and techniques impacting subsurface penetration performance and penetration rate are studied and analyzed. Two main dimensions are identified, and the works performed during operation were compared. A solution based on implementation of modular architecture of the system with optional connection of modules, performing computations according to various techniques, enabling comparison of calculation results and selection of the most effective option, is proposed. A computational experiment based on real-objects data was conducted. The factors effecting drilling-and-blasting operations were identified during its course. A model designing the optical projections over targeted drill holes is also obtained. The proposed approach is more effective and accurate than manual application of drill hole spacing by paint; in addition, is saves a lot of time required for setting-up. Another highlighted advantage of the developed approach is high quality and accuracy at marking of the drill hole spacing for blasting pattern in accordance with geometrical features of the surfaces, vs. approaches and techniques used at preparation to drilling earlier. Aside from that, a clear trend of consistent improvement and perfection by means of application of intelligent algorithm is observed in this scope.

Blasting Delay Pattern Development in the Light of Rockburst Prevention – Case Study from Polish Copper Mine

In order to reduce the risk of induced seismicity related to underground mining, a number of preventive actions are applied in the form of passive and active prevention methods. The former are mainly of an organisational nature and their effectiveness is usually considered in the long term, while the active methods are mostly based on the detonation of explosives and are aimed to release the seismic energy accumulated in the rock mass. In this paper, modifications of the firing pattern aimed to concentrate the paraseismic vibrations while maintaining the appropriate excavation of the mining face has been verified on the basis of underground tests. The evaluation was based on fragmentation analysis. The obtained results confirmed, that the blasting pattern modifications related to the reducing of the face firing time do not cause significant differences in terms of the appropriate excavation of the mining face.

Selection of Most Proper Blasting Pattern in Mines Using Linear Assignment Method: Sungun Copper Mine / Wybór Najodpowiedniejszego Schematu Prowadzenia Prac Strzałowych W Kopalni Miedzi Sungun Z Użyciem Metody Przyporządkowania Liniowego

One of the most important operations in mining is blasting. Improper design of blasting pattern will cause technical and safety problems. Considering impact of results of blasting on next steps of mining, correct pattern selection needs a great cautiousness. In selecting of blasting pattern, technical, economical and safety aspects should be considered. Thus, most appropriate pattern selection can be defined as a Multi Attribute Decision Making (MADM) problem. Linear assignment method is one of the very applicable methods in decision making problems. In this paper, this method was used for the first time to evaluate blasting patterns in mine. In this ranking, safety and technical parameters have been considered to evaluate blasting patterns. Finally, blasting pattern with burden of 3.5 m, spacing of 4.5 m, stemming of 3.8 m and hole length of 12.1 m has been presented as the most suitable pattern obtained from linear assignment model for Sungun Copper Mine.